Data refinement in optical systems

Abstract

The optical system is configured to output a system output signal such that a frequency of the system output signal changes in a series of repeated cycles. Each of the cycles includes multiple data periods. The frequency of the system output signal changes at different rates during different data periods. The optical system includes a light-combining component that combines light that returns to the optical system from the system output signal with light from a reference signal so as to generate a beating signal beating at a beat frequency. The system includes electronics that generate frequency change data that indicates a beat frequency change over time. The electronics can apply edge detection criteria and/or outlier detection criteria to the frequency change data.

The invention claimed is: 
     
         1 . A system, comprising:
 a LIDAR system configured to output a system output signal such that a frequency of the system output signal changes in a series of repeated cycles,
 each of the cycles includes multiple data periods,
 the frequency of the system output signal changing at a different rate during different data periods, 
 the LIDAR system being configured to scan the system output signal through multiple sample regions in a field of view; 
 
 the LIDAR system including a light-combining component that combines light that returns to the LIDAR system from the system output signal with light from a reference signal so as to generate a beating signal beating at a beat frequency, 
 the reference signal including light that has not exited from the LIDAR system; and 
   electronics generate frequency change data that indicates a beat frequency change over time, the beat frequency change being a change in the beat frequency between different data periods, and
 the electronics generating LIDAR data for each sample region in at least a portion of the multiple sample regions such that the LIDAR data generated for each sample region is generated between 2 and 6 data periods after scanning the sample region, and 
 the electronics using the beat frequency values as variables in calculations of the LIDAR data generated for each of the sample regions, 
 the LIDAR data generated for each sample region indicating a radial velocity and/or distance between the LIDAR system and an object outside of the LIDAR system and in the sample region, and 
 the electronics adjusting the LIDAR data in response to the frequency change data. 
   
     
     
         2 . The system of  claim 1 , wherein the frequency change data includes multiple beat frequency change values that each indicates a change in the beat frequency between the data periods in different cycles. 
     
     
         3 . The system of  claim 2 , wherein corresponding data periods in different cycles have the same rate of frequency change and each of the beat frequency change values indicates a change in the beat frequency between corresponding data periods in different cycles. 
     
     
         4 . The system of  claim 3 , wherein each of the cycles includes first data periods that correspond with a different data period in the other cycles and also includes second data periods that correspond with a different data period in the other cycles. 
     
     
         5 . The system of  claim 4 , wherein a first portion of the beat frequency change values indicates a change in the beat frequency between first data periods and a second portion of the beat frequency change values indicates a change in the beat frequency between second data periods. 
     
     
         6 . The system of  claim 5 , wherein the electronics apply criteria to the frequency change data so as to identify a data period where the system output signal illuminates an edge of a surface of an object, and the electronics adjust the LIDAR data in response to the identification of the data period. 
     
     
         7 . The system of  claim 6 , wherein the electronics apply edge detection criteria to the frequency change data so as to identify the data period where the system output signal illuminates an edge of a surface of an object. 
     
     
         8 . The system of  claim 7 , wherein the electronics use at least one beat frequency change value from the first portion of the beat frequency change values and at least one beat frequency change value from the second portion of the beat frequency change values to apply the edge detection criteria to the frequency change data. 
     
     
         9 . The system of  claim 7 , wherein fewer than 10 frequency change values are needed to apply the edge detection criteria to the frequency change data. 
     
     
         10 . The system of  claim 3 , wherein the electronics apply outlier detection criteria to the frequency change data so as to identify beat frequencies that are outliers and the electronics adjust the LIDAR data in response to the identification of the beat frequencies that are outliers. 
     
     
         11 . The system of  claim 10 , wherein outlier detection criteria use frequency change values from multiple different cycles, and
 each of the frequency change values in the outlier detection criteria indicates a change in the beat frequency between data periods that have the same rate of frequency change but are from different cycles.   
     
     
         12 . The system of  claim 10 , wherein the electronics apply edge detection criteria to the frequency change data so as to identify a data period where the system output signal illuminates an edge of a surface of an object, and
 the electronics apply the outlier detection criteria to a particular one of the data periods before the electronics apply the edge detection criteria to the particular data period.   
     
     
         13 . The system of  claim 1 , wherein the electronics are configured to use the beat frequencies from different data periods as a variable in calculating the LIDAR data for each of the sample regions in the portion of the sample regions. 
     
     
         14 . The system of  claim 1 , wherein the LIDAR data for each sample region is generated between 1 and 50 microseconds after scanning the sample region. 
     
     
         15 . The system of  claim 1 , wherein the
 electronics apply outlier detection criteria to the frequency change data so as to identify beat frequencies that are outliers, and   the electronics do not calculate the LIDAR data for a sample region when a beat frequency generated during the scan of the sample region is identified as an outlier.   
     
     
         16 . The system of  claim 1 , wherein the
 electronics apply edge detection criteria to the frequency change data so as to identify edge beat frequencies that each occur during one of the data periods where the system output signal illuminates an edge of a surface of an object during the data period,   the electronics adjusting the LIDAR data for one of the sample regions as a result one or more of the identified beat frequencies being a variable in a calculation that electronics use to calculate the LIDAR data for that sample region.   
     
     
         17 . The system of  claim 16 , wherein adjusting the LIDAR data for a sample region includes setting the LIDAR data for the sample region equal to the LIDAR data for a second sample region where none of the identified beat frequencies is a variable in the calculation that electronics use to calculate the LIDAR data for the second sample region. 
     
     
         18 . The system of  claim 1 , wherein the electronics are configured to identify one or more different patterns in the beat frequency change over time and to adjust the LIDAR data in response to the identification of one of the patterns. 
     
     
         19 . A method of operating a LIDAR system, comprising:
 transmitting a system output signal from the LIDAR system such that a frequency of the system output signal changes in a series of repeated cycles,
 each of the cycles includes multiple data periods,
 the frequency of the system output signal changing at a different rate during different data periods; 
 
   scanning the system output signal through multiple sample regions in a field of view;   combining light that returns to the LIDAR system from the system output signal with light from a reference signal so as to generate a beating signal beating at a beat frequency,
 the reference signal including light that has not exited from the LIDAR system; 
   generating frequency change data that indicates a beat frequency change over time, the beat frequency change being a change in the beat frequency between different data periods;   generating LIDAR data for each sample region in at least a portion of the multiple sample regions such that the LIDAR data generated for each sample region is generated between 2 and 6 data periods after scanning the sample region; and   adjusting the LIDAR data in response to the frequency change data,
 the LIDAR data generated for each sample region indicating a radial velocity and/or distance between the LIDAR system and an object located outside of the LIDAR system and in the sample region. 
   
     
     
         20 . A system, comprising:
 a LIDAR system configured to output a system output signal such that a frequency of the system output signal changes in a series of repeated cycles,
 each of the cycles includes multiple data periods,
 the frequency of the system output signal changing at a different rate during different data periods, 
 the LIDAR system being configured to scan the system output signal through multiple sample regions in a field of view; 
 
 the LIDAR system including a light-combining component that combines light that returns to the LIDAR system from the system output signal with light from a reference signal so as to generate a beating signal beating at a beat frequency, 
 the reference signal including light that has not exited from the LIDAR system; and 
   electronics generate frequency change data that indicates a beat frequency change over time, the beat frequency change being a change in the beat frequency between different data periods,
 the electronics generating LIDAR data for each sample region in at least a portion of the multiple sample regions such that the LIDAR data generated for each sample region is generated between 1 and 50 microseconds after scanning the sample region, 
 the electronics using the beat frequency values as variables in calculations of the LIDAR data generated for each sample region, 
 the LIDAR data generated for each sample region indicating a radial velocity and/or distance between the LIDAR system and an object that is outside of the LIDAR system and in the sample region, and, 
 the electronics adjusting the LIDAR data in response to the frequency change data. 
   
     
     
         21 . The system of  claim 20 , wherein the frequency change data includes multiple beat frequency change values that each indicates a change in the beat frequency between the data periods in different cycles. 
     
     
         22 . The system of  claim 21 , wherein corresponding data periods in different cycles have the same rate of frequency change and each of the beat frequency change values indicates a change in the beat frequency between corresponding data periods in different cycles. 
     
     
         23 . The system of  claim 22 , wherein each of the cycles includes first data periods that correspond with a different data period in the other cycles and also includes second data periods that correspond with a different data period in the other cycles. 
     
     
         24 . The system of  claim 23 , wherein a first portion of the beat frequency change values indicates a change in the beat frequency between first data periods and a second portion of the beat frequency change values indicates a change in the beat frequency between second data periods. 
     
     
         25 . The system of  claim 24 , wherein the electronics apply criteria to the frequency change data so as to identify a data period where the system output signal illuminates an edge of a surface of an object, and the electronics adjust the LIDAR data in response to the identification of the data period. 
     
     
         26 . The system of  claim 25 , wherein the electronics apply edge detection criteria to the frequency change data so as to identify the data period where the system output signal illuminates an edge of a surface of an object. 
     
     
         27 . The system of  claim 26 , wherein the electronics use at least one beat frequency change value from the first portion of the beat frequency change values and at least one beat frequency change value from the second portion of the beat frequency change values to apply the edge detection criteria to the frequency change data. 
     
     
         28 . The system of  claim 26 , wherein fewer than 10 frequency change values are needed to apply the edge detection criteria to the frequency change data. 
     
     
         29 . The system of  claim 22 , wherein the electronics apply outlier detection criteria to the frequency change data so as to identify beat frequencies that are outliers and the electronics adjust the LIDAR data in response to the identification of the beat frequencies. 
     
     
         30 . The system of  claim 29 , wherein outlier detection criteria use frequency change values from multiple different cycles, and
 each of the frequency change values in the outlier detection criteria indicates a change in the beat frequency between data periods that have the same rate of frequency change but are from different cycles.   
     
     
         31 . The system of  claim 29 , wherein the electronics apply edge detection criteria to the frequency change data so as to identify a data period where the system output signal illuminates an edge of a surface of an object, and
 the electronics apply the outlier detection criteria to a particular one of the data periods before the electronics apply the edge detection criteria to the particular data period.   
     
     
         32 . The system of  claim 20 , wherein the electronics are configured to use the beat frequencies from different data periods as a variable in calculating the LIDAR data for each of the sample regions in the portion of the sample regions. 
     
     
         33 . The system of  claim 20 , wherein the electronics apply outlier detection criteria to the frequency change data so as to identify beat frequencies that are outliers, and
 the electronics do not calculate the LIDAR data for a sample region when a beat frequency generated during the scan of the sample region is identified as an outlier.   
     
     
         34 . The system of  claim 20 , wherein the electronics apply edge detection criteria to the frequency change data so as to identify edge beat frequencies that each occur during one of the data periods where the system output signal illuminates an edge of a surface of an object during the data period,
 the electronics adjusting the LIDAR data for one of the sample regions as a result one or more of the identified beat frequencies being a variable in a calculation that electronics use to calculate the LIDAR data for that sample region.   
     
     
         35 . The system of  claim 34 , wherein adjusting the LIDAR data for a sample region includes setting the LIDAR data for the sample region equal to the LIDAR data for a second sample region where none of the identified beat frequencies is a variable in the calculation that electronics use to calculate the LIDAR data for the second sample region. 
     
     
         36 . The system of  claim 20 , wherein the electronics are configured to identify one or more different patterns in the beat frequency change over time and to adjust the LIDAR data in response to the identification of one of the patterns. 
     
     
         37 . A method of operating a LIDAR system, comprising:
 transmitting a system output signal from the LIDAR system such that a frequency of the system output signal changes in a series of repeated cycles,
 each of the cycles includes multiple data periods,
 the frequency of the system output signal changing at a different rate during different data periods; 
 
   scanning the system output signal through multiple sample regions in a field of view;   combining light that returns to the LIDAR system from the system output signal with light from a reference signal so as to generate a beating signal beating at a beat frequency,
 the reference signal including light that has not exited from the LIDAR system; 
   generating frequency change data that indicates a beat frequency change over time, the beat frequency change being a change in the beat frequency between different data periods;   generating LIDAR data for each sample region in at least a portion of the multiple sample regions such that the LIDAR data generated for each sample region is generated between 1 and 50 microseconds after scanning the sample region; and   adjusting the LIDAR data in response to the frequency change data,
 the LIDAR data for each sample region indicating a radial velocity and/or distance between the LIDAR system and an object that is located outside of the LIDAR system and in the sample region.